ABSTRACT
The R.F. D/F System 8. At one time H.F. D/F stations were pro\Tided at every airfield in the Command; this ,vas tIle
policy in February, 1942. Though an H.F. D/F station could not be relied upon to give reliable bearings at ranges much over 100 miles, it could in fact home an aircraft from much greater distances, the accuracy improving as the range shortened, until the final bearings would bring the aircraft right over the airfield. The sequence of using the ground-air aids on the r-eturn flight was therefore to obtain two or three fixes on M.F. while over the North Sea and then to change to the home station I-I.F. D/F for the final homing.
